AC_CACHE_CHECK([for lock-free atomic intrinsics], glib_cv_g_atomic_lock_free, [
AC_TRY_COMPILE([],
- [__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4;],
+ [volatile int atomic = 2;\
+ __sync_bool_compare_and_swap (&atomic, 2, 3);],
[glib_cv_g_atomic_lock_free=yes],
[glib_cv_g_atomic_lock_free=no])])
SAVE_CFLAGS="${CFLAGS}"
CFLAGS="-march=i486"
AC_TRY_COMPILE([],
- [__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4;],
+ [volatile int atomic = 2;\
+ __sync_bool_compare_and_swap (&atomic, 2, 3);],
[AC_MSG_ERROR([GLib must be build with -march=i486 or later.])],
[])
CFLAGS="${SAVE_CFLAGS}"
fi
+# Some compilers support atomic operations but do not define
+# __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4, like clang
+if test x"$glib_cv_g_atomic_lock_free" = xyes; then
+ AC_TRY_COMPILE([],
+ [__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4;],
+ [],
+ [AC_DEFINE(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4, 1, [ compiler supports atomic operations])])
+fi
+
dnl We need a more robust approach here...
case $host_cpu in
i?86|x86_64|s390|s390x|arm*|crisv32*|etrax*)